B&W film speeds Was[APML] Konica Centuria 400 now gone

[George Anderson <georgea@cam.org>]

Hi Don

I was aware that the Centuria 400 was colour negative film. I should
have changed the subject line.
For the film speed I was talking to Joe about how some of the B&W films
are listed at one speed but the true speed of the film is slower. As an
example Ilfords Delta 3200 lists 3200 ISO as its prime speed, but in the
tech sheet Ilford state that the film is actually a 1000 ISO that pushes
very well. Joe had stated that the Forte-Pan 400 was actually a 200 ISO
film and I was wondering if that was a measured 200 ISO at the
recommended developing, or if the film was a 200 ISO which gets a one
stop push in developing. If this is the case when it is processed at 200
I would expect finer grain.

George Anderson
Montreal Canada

Clear skies and good health

Don Westergren wrote:
> 
> George,
> 
> The Konica is a color negative that is processed with the C-41 process.
> Most of those are automatic machines where the operators won't increase nor
> decrease developing.  The ASA for these films means very little when you
> shoot astrophotos for many minutes to hours.  The reciprocity determines
> what you will get.  Basically the grain you get will be what the film gives
> you, unaffected by how long you expose it.
> 
> Don
> 
> >
> >
> > Joseph O'Neil wrote:
> > > Hi;
> > >          I have yet to hyper some.  Shoot a few boxes of it daylight.
> Nice
> > > stuff, but the 400 ASA is really a 200 ASA, but otherwi9se is hard stuff
> to
> > > mess up.   I haven't had a chance to do squat this year, but I plan to
> get
> > > some eventually, hyper a roll,a nd see how it works out.  Cheap enough
> though.
> > >
> > >          In Canada, Eight elm Camera stocks it, and in the USA< you can
> get
> > > it from here
> > >
> > > http://www.jandcphotography.com/
> > >
> > >          J&C specializes in hard to find B&W films, form 35mm to sheet
> > > films,s o wroth a look.  Thier "house brand" J&C film  film, is, I am
> 99%
> > > certian ,  Forte Pan from Hungary.    at least the specs are nearly
> identical.
> > >
> > >          Anyhow, for those of you looking for hard to find B&W films,
> worth
> > > a web link.
> > > joe
> > >
> > > http://www.oneilphoto.on.ca
> > > http://www.multiboard.com/~joneil
> > > Una salus victis, nullam sperare salutem
> >
> > Thanks Joe
> >
> > Do you process it at 200 or 400? Just curious if the grain will be finer
> > when processed at the slower speed. I should be receiving two rolls in a
> > week or so.
> > I am also planning on checking out the Ilford Delta 400 and just for fun
> > the Delta 3200. The 3200 may make a good B&W process at home film for
> > someone just starting out.
> > The specs on both films show a 2 stop loss after 2 minutes, but the
> > sensitivity does extend to 700nm. Once my gas arrives I may have a go at
> > seeing how the 400 responds to hypering. I have about 4 B&W films to
> > test. Just wish we had some clear nights.
> >
> > George
> >
> > Clear skies and good health
> > _______________________________________________
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> > Astro-Photo@seds.org
> > http://seds.org/mailman/listinfo/astro-photo
> >
> >
> 
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